This file contains information about the normal estimator for point clouds. 
The implementation refers to the paper from Symposium of Geometry Processing 2012,
"Fast and Robust Normal Estimation for Point Clouds with Sharp Features".
The code is developped at the Center for Visual Computing of the LIGM 
(Paris Est university - Ecole Nationale des Points et Chaussees).

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EXAMPLE OF USE
################################################################################
example of .cpp file to estimate normals

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#define USE_OPENMP_FOR_NORMEST //you don't want to use OPENMP comment this line

#include CGAL_normEst.h

typedef CGAL::Simple_cartesian<float> Kernel;
typedef CGAL::Point_3<Kernel> Point3;
typedef CGAL::Vector_3<Kernel> Vector3;

int main(){

  ...
  std::vector<Point3> points;
  ... // filling the vector with the point cloud

  std::vector<Vector3> normals;

  CGAL_Normal_Estimator NE(points,normals);
  
  //change values of the parameters
  NE.number_of_planes() = 500;
  NE.normal_selection_mode() = CGAL_NORMAL_ESTIMATOR::MEAN;

  //estimate the normals
  NE.estimate() // with default parameters
  NE.estimate(CGAL_NORMAL_ESTIMATOR::CUBES, CGAL_NORMAL_ESTIMATOR::RADIUS, 0.1); //changing method

  ...

  return 0;
}



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#################################################################################
LICENSE INFORMATION
#################################################################################
Copyright (C) 2012 Boulch Alexandre, Ecole Nationale des Ponts et Chaussees - 
Ecole des Ponts ParisTech

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Note that this library relies on external libraries subject to their own license.
To use this software, you are subject to the dependencies license, these licenses 
applies to the dependency ONLY and NOT this code.
Please refer below to the web sites for license informations.

OPENMP (http://openmp.org/)

CGAL (http://www.cgal.org/) see CGAL Licence Term.
Following lines describe CGAL license and can't be considered as the license, 
please refer to (http://www.cgal.org/) 

Since release 3.0, CGAL is available under an Open Source license as well as a commercial
 license. Users choosing to use CGAL under the free-of-charge Open Source license have to 
comply to its terms, otherwise they have to buy a commercial license.
Starting from release 4.0. CGAL is available under the GPL/LGPL, while releases 3.x were 
distributed under the QPL/LGPL. These license changes are not fundamental, that is, the 
licenses are similar in their spirit, and the change reflects the fact that the QPL has 
become marginal, since it had been introduced and later abandoned for Qt.
We informally describe below our license scheme, that is, which rights we give to users.
 Also, do not hesitate to contact us for any question regarding the license.

The Open Source License
Some parts of CGAL are available under the LGPL, other parts are under the GPL. These two 
licenses introduce different constraints.
The idea is that the fundamental building blocks of CGAL are under the LGPL because this 
is a less constraining license which allows more people to build on top of this code 
without much constraints. This helps making the CGAL design a de-facto standard for geometric
 code which helps interoperability. The higher-level algorithms are typically released 
under the GPL in order to protect their commercial value. This makes it possible for us to 
exploit it commercially, which guarantees long term support, maintenance and further 
developments of the code for the benefit of the project and its users.
The Package Overview web page gives the license of each package. Approximately, the Kernel 
and Support libraries are under the LGPL, and most geometric algorithms and data structures 
are under the GPL, but there are some exceptions in both directions.
For the exact and formal details of the license, please always refer to the LICENSE file 
from the CGAL source code distribution.

The LGPL
The Lesser General Public License (v3+) gives you the right to use and copy the code freely. 
It is also possible to modify the code under the condition that the resulting modification 
is released as source code under the LGPL with any binary distribution of your software that 
uses these LGPL parts.

The GPL
The GPL (v3+) is an Open Source license that, gives you the right to use, copy and modify the 
code freely. If you distribute your software based on GPLed CGAL data structures, you are 
obliged to distribute the modifications of CGAL you made, and you are furthermore obliged to 
distribute the source code of your own software under the GPL.

The Commercial License
In cases where the constraints of the Open Source license prevent you from using CGAL, you 
can buy a commercial license for CGAL or parts of CGAL from GeometryFactory. The commercial 
offer is adapted to academic/research and industry customers.


